Sub Feature for specific instances

In a type family I’d like to substitute a specific glyph only when it is followed by SPACE; and only in certain styles;
For example, I’ve created a special E.Ornament letter;
Sub E’ Space’ by E.Ornament
wondering if the Sub Feature could be applied for specific instances only !
Not sure if this thread is a similar case:
Or is there a another way to resolve by custom parameter !

Maybe the Replace Feature parameter can help you.

You can do a contextual substitution with space in the context. But it will not work everywhere since not all renderers use the space glyph for the word space. Rather use an ignore statement to be on the safe side.